Method of covering electric conductors and making cables.



No. 699,458. Patented Maiy 6, I902.

H. W. DOVER. v I METHOD OF COVERING ELECTRIC GONDUGTORS AND MAKINGGABLES.

(Appliqation filed Feb. 1, 1902.) I

(No Model.) 5 Shaets-Sheet l.

Patented May 6, I902.

H. W. DOVER. METHOD OF COVERING ELECTRIC CONDUCTOBS AND MAKING CABLES.

(Applicatiqn filed Feb. 1, 1902.)

5 Sheets-8heet 2.

(No Model.)

MOT/V701? fforacewarer us ca. wovoufuo. wnsumm'ou.

"No. 699,458; Patented ma 6,1902.

. H. w. novsn.

METHOD OF COVERING ELEGTBIGJCONDUGTORS AND MAKING CABLES.

(Application filed Feb. 1, 1902.) v (Ilo Model.) .SShaets-Shoet 3.

pm. 699,458. Phtented Mayfi, I902.

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METHOD 0F CDVERING ELECTRIC CONDUCTORS AND MAKING GABLES.

' (Application filed Feb. 1, 9902. (No Model.) 5 Sheets-Sheet 4.

'n-i! NORRIS PETERS co, moruumu. WASHINGTON, n. c.

No. 699,458. Pajented May 6, I902;

H. W. DOVER. METHOD OF COVEBING'ELECTRIC CONDUCTOBS AND MAKING GABLES.(Application filed Feb. 1, 1902.)

.s (No Model.) 5 Sheets-Sheet 5.

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UNTTED STATES PATENT ()FFICE.

HORACE WALTER DOVER, OF NORTHAMPTON, ENGLAND.

METHOD OF COVERING-ELECTRIC CONDUCTORS AND MAKING CABLES.

SPECIFICATION forming part of Letters Patent No. 699,458, dated May 6,1902.

Application filed February 1, 1902. Serial No. 92,226. (No model.)

To aZZ whom it may concern:

Be it known that I, HORACE WALTER Do- VER, managing director of Dover,Limited, a subject of the King of Great Britain, residing at Park road,St. James End, Northampton, England, have invented new and usefulImprovements in Methods of Covering Electric Conductors and MakingCables, of which the following is a specification.

This invention relates to an improvement in the method of covering wires(whether plain or stranded {and whether singly or in pairs or groups)with celluloid, xylonite, or similar material.

The invention relates to the manufacture of telephonic and telegraphiccables at a single operation by the application of the insulating andprotective material simultaneously to the conductor or conductors and towire or fibrous cords used to impart tensile strength to the cable andwhich are protected from the destructive influences of the air or waterby the covering of insulating material in which they are embedded. Theinsulating material is applied to the wire or wires and cords byextrusion in the plastic state through a die, which is traversed by thewire or wires and cords to be covered, a twist being at same timeimparted which is rendered permanent by the setting of the insulatingmaterial.

The invention will be described with reference to the accompanyingdrawings, forming part of this specification, wherein are representedforms of tools respectively adapted for covering multiple wires andstranded wires or cords, together with sections-of the covered wires orcables produced.

Figure 1 is a longitudinal sectional view, and Figs. 2 and 3 are endviews of a tool for covering a plurality of wires and incorporating themat one operation in the form of a cable, as shown in cross-section inFig. 4. Figs. 5, 6, 7 are similar views of a tool for similarly coveringand incorporating in cable form a central stranded conductor surroundedby wire or fibrous cords to impart the tensile strength required for asubmarine cable, as shown in Fig. 8. Figs. 9 and 10 show a modification,and Fig. 11 shows a cross-section of the cable. Fig. 12 is a frontelevation, and Fig. 13 a side elevation, of

apparatus for imparting twist to the cable or taking up twist impartedby the die.

Referring to Figs. 1, 2, 3, 4-, A is the die- 'boX, screwed to orotherwise connected with the steam-jacketed pressure-chamber B of astuffing machine or press capable of exerting a pressure of, say, oneand onefourth tons per square inch. The chamber a of the die-box is incommunication with the pressure-cylinder by an orifice b, and terminatesin a coned portion a leading to an orifice (F, with parallel sides orvery slightly coned, the length of the orifice a being such as to insurea sufficient grip of the wires by the covering material to cause theWires to be fed through along with the covering material withouttensionbeing otherwise applied to the wires.

0 represents tubular guide mandrels or wire guides, each formed of asteel tube, the several tubes being mounted in and traversing a bush E,which closes the rear end of the,

distance between the circles themselves, the

guide-mandrels are given a slight spiral inclination alternately to theright and the left hand for successive circles, so that theguidemandrels of adjacent circles lie across each other and areprevented from being forced, those of the one circle into the spacebetween those of the other circle, the guide-mandrels being taperedtoward the exit-nozzle. This opposite-handed twist of the guide-mandrelsis shown in Fig. 1 by a portion of the outer circle of guide-mandrelsbeing broken out to show the opposite twist of the circle C ofguide-mandrels immediately within, the alternation of twist beingrepeated for the remainder of the circles, the central guide-1nandrelalone being straight.

As the guide-mandrels are widely separated toward the bush E andgradually converge toward the exit-nozzle, the intervening spaces are ofgradually-decreasing sectional area in the direction of the flow of theinsulating material, so that while easy admission for the material tothe innermost spaces between the guide-mandrels and a uniformdistribution of the material is provided for an increase in the densityof the material consequent on its forcible extrusion through passages ofdiminishing area will be insured, while the direction of movement of themass of material at the point of emergence from between theguide-mandrels is caused to so nearly approach the direction of thewires passing through the nozzles as to insure that the wires shall bedrawn through the guide-mandrels, in which they are an easy fit.

dis a circumferential channel separated from the space a by a liner-ringd, but communicating therewith by orifices d the liner having for effectto divert the material entering at I) in opposite directions through theannular channel cl, whence it passes through the orifices d which are sospaced and so graduated in diameter as to equalize the flow of materialthroughout the die-chamber.

The insulating material on emerging through the spaces between theclosely juxtaposed guide-mandrels being still plastic coalesces in theform of a solid mass around and between the wires which are thusembedded therein, so as to form a cable in which the wires are severallyinsulated from each other and from external influences.

In order to admit of the cable being coiled on a drum and uncoiled orunwound without straining or kinking the wires, a twistwould be impartedto the cable before the insulating material becomes set, so as to causethe wires to assume a spiral form of long pitch around the central wire,this twist becoming permanent by the subsequent setting of the material.The twist would be imparted by making the drum on which the cable iswound after leaving the nozzle rotate both aboutits own axis and alsoabout an axis at right angles thereto, as hereinafter described inreference to Figs. 12 and 13.

The tool shown in Figs. 5, 6, and 7 is substantially similar to thatabove described, except that the guide-mandrels are of larger diameterin order to give passage to stranded wires or cords adapted the centralone to act as the electric conductor and the outer ones to impart thenecessary tensile strength to a cable for submarine purposes. Theguidemandrels converge toward the extrusion-nozzle, so that theintervening spaces for the pas-' sage of the insulating material will beof gradually diminishing sectional area toward the point of emergence,the tubes being externally tapered to a sharp edge toward the nozzle, soas to enable the insulating material to be delivered from theintervening passages closely around the stranded wires or cords. In thiscase the outer guide-mandrels may be spirally inclined all in the samedirection about the central guide-mandrel, so as to cause a twist to beimparted to the cable while being extruded, the nozzle beingcorrespondingly rifled, as shown in 'Figs. 9 and 10, so as to assist inimparting the desired twist and economize insulating material by givingthe cable the section shown in Fig. 11. The amount of twist thus putinto the tension strands or cords by the rifling of the die-nozzle andthe spiral inclination of the guide-mandrels would in this case beallowed for or maintained in winding the cable 011 a drum by means ofthe apparatus shown in Figs. 12 and 13 and hereinafter described, thetwist Y thus received being rendered permanent by the setting of theinsulating material, while the cable remains in the coiled form.

The apparatus for imparting twist to the cable after extrusion from thedie or for taking up the twist imparted to the cable by the die, formedas described in reference to Fig. 9, is shown in Figs. 12 and 15. Itconsists of a drum F, on which the cable a: is wound, carried by aspindle f, mounted to revolve in hearings in Crossbars of a cylindricalframe G, having its axis at right angles to the drumspindlef andsubstantially in alinement with the nozzle, (not shown in Figs. 12 and13,) from which the cable is extruded. The frame G may be formed of apair of flanged rings g, braced by cross-bars and mounted to rotateabout its own axis on pairs of grooved rollers H, carried by axles h,mounted in hearings on a trolley I, supported on wheels J, adapted torun to and fro on railsj at right angles to the line of pull, so as toenable the cable to be laid evenly on the drum. The frame G is revolvedabout its own axis by a worm -shaft K, driven by any convenient power,having worms 7c, which gear with worm-wheels L, fast on the spindle h,the rollers H rotating the frame G by frictional contact with the ringsg, resting thereon, the rotation of the frame G causing the drum to berotated about an axis at right angles to its own axis f. The drum F isat same time rotated about its axis for the purpose of winding up thecable by a worm-wheel M, journaled in a bearing on the cross-bars of therotating frame'and engaging with the squared spindle f, the worm-wheelbeing in gear with a worm m upon a spindle it, mounted in bearings onthe rotating frame and having a pinion N fast on its end, which gearswith and revolves about a stationary spur-wheel P, fixed upon thetrolley-frameI coaxially with the revolving frame G, so that as thelatter frame is rotated the drum will likewise be rotated, the combinedmotion putting the desired twist into the cable 00 and at same timewinding the cable on the drum. The squared spindle f engages in acorresponding hole in thedrumF and through a cylindrical boss f, forminga journal for the drum at the one end, the journal of the worm-wheel Msupporting the drum at the other end. The spindlefis suitably secured inposition and may be withdrawn for the purpose of removing the drum.

I claim The herein-described method of making an form a cable whereinthe individual wires and 10 electric cable formed of a plurality ofwires strands areinsulated from each other and are or strands or wiresand strands embedded or twisted about the central wire or strand, asinclosed in celluloid, xylonite or similar lnadescribed. 5 terial byforcing the material under pressure through a die and around and betweenthe HORACE VALTER DOVER wires orstrands passing through the die andWVitnesses: at same time imparting a twist to the cable T. W. KENNARD,

thus formed so as, at a single operation, to 1 J. CONWAY.

